Fix handling of weak frameworks with path names.
Fix handling of weak frameworks with path names.

Previously if a path to a framework to be weakly linked was given (as
opposed to a framework name), it was strongly linked. The correct flag
to mark the library path as weakly linked is now applied.

Change-Id: I523fd84ba0967e68906611b32305aaf371b1a6b4
Reviewed-by: Joerg Bornemann <47777b9406dbddd02a3fdca8341789a013805a11@digia.com>

Distrotech/qbs,villytiger/qbs,Distrotech/qbs,gatzka/qt-labs-qbs,qt-labs/qbs,gatzka/qt-labs-qbs,qt-labs/qbs,villytiger/qbs,Distrotech/qbs,qtproject/qt-labs-qbs,qt-labs/qbs,Distrotech/qbs,qt-labs/qbs,Distrotech/qbs,villytiger/qbs,villytiger/qbs,gatzka/qt-labs-qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,villytiger/qbs,Distrotech/qbs,qt-labs/qbs,qtproject/qt-labs-qbs,gatzka/qt-labs-qbs,Distrotech/qbs,gatzka/qt-labs-qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qt-labs/qbs,villytiger/qbs,gatzka/qt-labs-qbs,qtproject/qt-labs-qbs,gatzka/qt-labs-qbs